Box 8D Steppe and arid landscapes

Semi-desert, Prikaspiyskaya, Russia

Source: redrawn from J Meeus


East of the well-known Hungarian puszta landscape (see below), an east­west oriented belt of steppe/grasslands stretches from the central Russian uplands to the Caspian and Black Seas. These 'steppes' are vast treeless plains with low rainfall. In the lowlands, northwest of the Caspian Sea, the steppes form a transitional zone with deserts ­ areas known as semi-desert (see below) (Anon, 1988). Only further to the east of the lower Volga, on the continental divide with Asia (eg, in Kazakhstan), can true desert be found. Arid landscapes also exist in the western extremities of Europe, in the Iberian Peninsula and the Canary Islands (see Chapter 9).

Puszta

On the loess plateaus of the Hungarian plain, climate and vegetation are of a steppe nature. The landscape is open with grassy vegetation, and trees remain only in valleys. Farm plots are large and concentrated, and some are collective (Kostrowicki et al, 1984; Csati et al, 1980). Because of dryness during the summer, the fertile chernozems and phaeozems (reddish prairie soils) are used mainly for livestock breeding, but arable crops may also be grown. Highly mechanised and productive agricultural systems are separated from the less intensive ones. The most serious hazards are wind and water erosion.

Semi-desert

The sparse, open vegetation of steppe grasses is mixed with drought-resistant dwarf shrubs and ephemeral plants, which grow during the extremely short rainy season. Especially in depressions with solonetz and solonchaks soils, saltmarsh and halophytic vegetation can be found. Aridity, dryness and deep water tables are responsible for salinisation and alkalisation of the soil. Apart from the salinated solonchaks there are the calcisols, with their topsoil concentrations of calcium carbonate. The organic matter content of the surface of calcisols is low because of a sparse vegetation and rapid decomposition of vegetable debris (Driessen and Dudal, 1991). Sheep and cattle herds may graze in spring and autumn, but only where grazing remains extensive. The increase of anthropogenic influence and the lowering of the water table are the factors responsible for desertification of the meadow-steppe. The degree of salinisation and swamping but also the length of the flood periods are indicators of the productivity of the landscape (Zalibikov, 1992).